Suturing instrument

ABSTRACT

The suturing instrument includes an elongate member having an articulating distal portion biased offset from the elongate member, and a sheath slideably disposed about the elongate member. The user positions the sheath in contact with the articulating distal portion to actuate the distal portion relative to the elongate member. The articulating distal portion is pivotally coupled to the elongate member for improved maneuverability within the body of a patient during surgical procedures.

TECHNICAL FIELD

The invention relates to devices and methods for placing sutures.

BACKGROUND INFORMATION

For many surgical procedures, it is necessary to make a large opening inthe human body to expose the area that requires surgical repair. Thereare instruments available that allow for viewing of certain areas of thehuman body through, for example, a natural body opening or a smallpuncture wound, and thus avoid the need for making such large openings.These instruments, called endoscopes, can be used in conjunction withspecialized surgical instruments to detect, diagnose, and repair areasof the body that previously required open surgery to access.

Some surgical instruments used in endoscopic procedures are limited bythe manner in which they access the areas of the human body in need ofrepair. In particular, the instruments may not be able to access tissueor organs located deep within the body or that are in some wayobstructed and inaccessible. In addition, many of the instruments arelimited by the way they grasp tissue, apply a suture, or recapture theneedle and suture. Furthermore, many of the instruments are complicatedand expensive to use due to the numerous parts and/or subassembliesrequired to enable them to function properly. Suturing remains adelicate and time-consuming aspect of most surgeries, including thoseperformed endoscopically.

Suturing instruments, and more specifically suturing instruments used inendoscopic procedures, are generally rigid and do not provide theoperator a range of motion to access difficult to reach parts of theanatomical region requiring sutures. Accordingly, multiple instrumentsof various configurations and sizes must be used to access all of thenecessary tissue areas. These limitations of suturing instrumentscomplicate the endoscopic procedure for the surgeon by requiring theinsertion and removal of multiple instruments from a surgical site asthe target suturing area changes during the course of the surgicalprocedure.

SUMMARY OF THE INVENTION

The invention generally relates to a medical device for performing asurgical procedure, such as passing a suture through tissue. Moreparticularly, in one embodiment, the invention is directed to a suturinginstrument including an articulating distal portion pivotally coupled tothe elongate member for improved maneuverability and functionalityduring surgery. According to one feature, the suturing instrument isdimensioned and configured to apply sutures to approximate, ligate, orfixate tissue in, for example, open, mini-incision, trans-vaginal,laporoscopic, or endoscopic surgical procedures.

In a first aspect, the invention is directed to a suturing instrumentincluding an elongate member and a sheath slideably disposed about theelongate member. The elongate member includes a longitudinal axis and adistal portion biased offset from the longitudinal axis. The sheathactuates the distal portion of the suturing instrument relative to thelongitudinal axis by direct contact with the distal portion.

In one embodiment according to the first aspect of the invention, thedistal portion is pivotally coupled to the elongate member. In anotherembodiment, the distal portion is biased up to about 90 degrees relativeto the longitudinal axis. In a further embodiment, the distal portionspans a range of actuation from about 1 degree to about 90 degrees.

In a second aspect, the invention relates to a suturing instrumentincluding an elongate member and a head coupled to a distal portion ofthe elongate member. A movable sheath is disposed about the elongatemember and slideable along a length of the elongate member. The sheathincludes a distal end with a tab extending therefrom and a fastenercoupling the tab of the sheath to the head. Sliding the sheath in aproximal direction causes the head to pivot.

In various embodiments according to the second aspect of the invention,the fastener couples the tab extending from the sheath via a slotdefined by the tab. Sliding the sheath in a proximal direction causesthe tab to engage the fastener, thereby pivoting the head. The sheathextends substantially the entire length of the elongate member. In afurther embodiment according to this aspect of the invention, slidingthe sheath in a proximal direction relative to the elongate memberbiases the head offset from the longitudinal axis of the elongatemember. Sliding the sheath in a distal direction causes the head topivot into substantial alignment with the longitudinal axis.

In various embodiments according to the foregoing aspects of theinvention, the suturing instrument includes a needle deploymentmechanism that is at least partially housed in the elongate member. Inanother embodiment of the invention, the suturing instrument includes aneedle carrier and an actuator at least partially disposed within theelongate member and coupled to the needle carrier. The needle carriermay include a distal portion that defines a lumen for receiving theneedle. With this arrangement, the needle is advanced out of an openingdefined by the head by the actuator. In a further embodiment, thesuturing instrument includes a needle catch disposed on the head andconfigured to receive the needle. The head or distal portion of thesuturing instrument may rotate relative to the elongate member.Additionally, the elongate member of the suturing instrument may includea push rod and spring arrangement for biasing the distal portion offsetfrom the longitudinal axis.

In a third aspect, the invention relates to a suturing instrument havingan elongate member including a longitudinal axis, a head pivotallycoupled to the elongate member, and a needle deployment mechanism atleast partially housed within the elongate member. The needle deploymentmechanism includes a needle carrier at least partially disposed in thehead for holding a needle and a carrier activation wire coupled to theneedle carrier and extending along the longitudinal axis of the elongatemember. When in tension, the activation wire biases the head offset fromthe longitudinal axis of the elongate member. When in compression, theactivation wire articulates the head relative to the longitudinal axisand preferentially deploys the needle from the head.

In various embodiments according to the foregoing aspect of theinvention, the suturing instrument includes a sheath disposed about theelongate member and slideable along a length of the elongate member. Thesheath includes a distal end for engaging and articulating the headrelative to the longitudinal axis of the elongate member. In additionalembodiments, the head of the suturing instrument is biased up to about90 degrees relative to the longitudinal axis. In another embodiment, thehead spans a range of actuation from about one degree to about 90degrees. In a further embodiment, the suturing instrument includes aneedle catch disposed on the head and configured to receive the needle.The needle carrier may include a distal portion that defines a lumen forreceiving the needle. In a further embodiment, the head is biased offsetfrom the longitudinal axis by a push rod and spring arrangement at leastpartially disposed in the elongate member.

Advantages and features of the present invention herein disclosed willbecome apparent through reference to the following description, theaccompanying drawings, and the claims. Furthermore, it is to beunderstood that the features of the various embodiments described hereinare not mutually exclusive and can exist in various combinations andpermutations.

BRIEF DESCRIPTION OF THE DRAWINGS

In the drawings, like reference characters generally refer to the sameparts throughout the different views. Also, the drawings are notnecessarily to scale, emphasis instead generally being placed uponillustrating the principles of the invention. In the followingdescription, various embodiments of the invention are described withreference to the following drawings, in which:

FIG. 1 is a schematic perspective view of one embodiment of a suturinginstrument in accordance with the invention;

FIG. 2A is a schematic plan view of another embodiment of a suturinginstrument in accordance with the invention;

FIGS. 2B and 2C are schematic cross-sectional views of the proximal anddistal portions, respectively, of the suturing instrument of FIG. 2A;

FIG. 2D is a schematic perspective view of various internal componentsof the suturing instrument of FIG. 2A;

FIG. 2E is an enlarged view of a portion of the suturing instrument ofFIG. 2D;

FIGS. 3A to 3C are detailed schematic views of the distal portion ofanother embodiment of a suturing instrument in accordance with theinvention;

FIG. 4A is a schematic perspective view of yet another embodiment of asuturing instrument in accordance with the invention;

FIGS. 4B and 4C are detailed schematic views of the distal portion ofthe suturing instrument of FIG. 4A;

FIG. 5 is a schematic detailed view of a distal portion of anotherembodiment of a suturing instrument in accordance with the invention;and

FIG. 6 is a schematic view of a clinical application of the suturinginstrument of FIG. 5.

DESCRIPTION

Embodiments of the invention are described below. It is, however,expressly noted that the invention is not limited to these embodiments,but rather the intention is that variations, modifications, andequivalents that are apparent to a person skilled in the art are alsoincluded.

A suturing instrument according to the invention is used, for example,to access areas within a human body to ligate, fixate, or approximatetissue. The suturing instrument throws one or more stitchesintercorporeally. FIG. 1 depicts the general structure of a suturinginstrument 100, according to an illustrative embodiment of theinvention, including a handle 102, an elongate member 104, a distalportion 106, and a proximal portion 108. The elongate member 104 ismechanically coupled to the handle 102 at the proximal portion 108 and aneedle deployment mechanism 110 is at least partially disposed withinthe distal portion 106 of the suturing instrument 100. The handle 102may take a variety of forms in various embodiments. For example, thehandle 102 may be one of the types used with Boston ScientificCorporation's suturing systems, in particular, those handles used withthe Capio® Push & Catch suturing system. The distal portion 106 ispivotally coupled to the elongate member 104. The distal portion 106 isactuated by, for example, an actuation means disposed within the handle102 or via the needle deployment mechanism 110.

In accordance with one illustrative embodiment of the invention, FIG. 2Adepicts a suturing instrument 200 including a handle 202, an elongatemember 204, and a needle deployment mechanism 210. The suturinginstrument 200 also includes a distal portion 206 and a proximal portion208. An articulation joint 212 pivotally couples the distal portion 206to the elongate member 204. The articulation joint 212 may be a clevis,hinge, ball-and-socket joint, or other suitable arrangement, whichpermits the distal portion 206 to articulate with respect to theelongate member 204. The elongate member 204 is mechanically coupled tothe handle 202 at the proximal portion 208 and the suturing componentsare at least partially disposed within the distal portion 206 of thesuturing instrument 200.

With continued reference to FIG. 2A, the needle deployment mechanism 210extends longitudinally through the elongate member 204 to the distalportion 206 of the suturing instrument 200, where the needle deploymentmechanism 210 is coupled to a needle carrier 258 (see FIG. 2C). Theneedle deployment mechanism 210 moves the needle carrier 258 between aretracted position and a deployed position.

FIGS. 2B and 2C are cross-sectional views of the proximal portion 208 ofthe suturing instrument 200 (FIG. 2B) and the distal portion 206 of thesuturing instrument 200 (FIG. 2C). Referring first to FIG. 2B, theproximal portion 208 of the suturing instrument 200 includes the handle202, the elongate member 204, and the needle deployment mechanism 210.In one embodiment, an optional suture clip 214 is coupled to the handle202 or the elongate member 204 and holds an end of one or more suturesprior to placement in a patient. The needle deployment mechanism 210includes an actuator 216 (including an actuator button 218 and a shaft220), a bearing 222, a button end 224, and a hole 226. The bearing 222rides along a cylindrical surface 228 that is formed by the insidediameter of the elongate member 204. A wireform 230 is inserted into thehole 226 of the shaft 220, coupling it to the actuator button 218. Asubstantially helical spring 232 encircles the wireform 230, abuts thebutton end 224, and is compressed between the button end 224 and a pushtube 234. The push tube 234 is seated upon a center tube 236 disposedwithin the elongate member 204. The center tube 236 is housed by thecylindrical surface 228 and is constrained in the distal portion 206. Apusher wire 240 is attached to the wireform 230 by means of a weld, acoupling, adhesive, or other attachment means, and is slidably disposedwithin a guidance sleeve 242, the sleeve 242 being disposed within acylindrical surface 244 formed by the inside diameter of the center tube236. In one embodiment, the pusher wire 240 is constructed of a shapememory material, such as nitinol. Nitinol is a nickel-titanium alloy.Preferably, the shape memory material is chosen for its combination ofproperties that allow for bendability and high column strength whenconstrained.

Referring to the illustrative embodiment of the invention depicted inFIG. 2C, the distal portion 206 of the suturing instrument 200 includesthe elongate member 204 pivotally connected to the distal portion 206 bythe articulation joint 212. The distal portion 206 includes a curvedportion 248 and a needle catch 250. The pusher wire 240, disposed withinthe center tube 236 is attached by welding or other means to a ferrule252, which is slidably disposed within a track 254. The ferrule 252 isattached to a carrier activation wire 256, which by virtue of itsattachment to the ferrule 252 is also slidably disposed within the track254. The carrier activation wire 256 is mechanically coupled to anextendable needle carrier 258 by a weld, a coupling, adhesive, or othermeans. The ferrule 252 is slideably disposed about the pusher wire 240.The track 254 provides a bearing surface for the translational movementof the ferrule 252. A push rod 260 is disposed longitudinally along theelongate member 204, having a distal end 262, which engages the distalportion 206 of the suturing instrument 200 at a pocket 268 disposed inthe distal portion 206.

The distal portion 206 is pivotally attached to the suturing instrument200 by the articulation joint 212. The articulation joint 212 isdisposed in the elongate member 204 proximate the distal portion 206.The articulation joint 212 facilitates the rotation about an angle θ forpositioning of the distal end 206 of the suturing instrument 200relative to a longitudinal axis 279. In addition, in some embodiments,the elongate member 204 is substantially linear or includes one or morebends to orient specifically the distal portion 206 of the suturinginstrument 200 to engage the location of suture placement. Thearticulation joint 212 and/or bend(s) along the elongate member 204 mayfacilitate access to deep and/or difficult to reach areas within thehuman body. The curved portion 248 of the distal portion 206 defines achannel 274 and an opening (or needle exit port) 276. The needle carrier258 is slideably disposed within the channel 274.

FIGS. 2D and 2E depict the internal assembly of various components ofthe suturing instrument 200 and the needle deployment mechanism 210 ingreater detail. The pusher wire 240 is attached directly to a distalportion of the shaft 220 and the push rod 260 is attached to the shaft220 at the push tube 234, the push tube 234 being disposed proximate tothe distal portion of the shaft 220. There are a variety of ways tosecure the pusher wire 240 and push rod 260 to the distal end of theshaft 220, e.g., welding, adhering, and threading. In some embodiments,depression of the button 218 translates to movement along a distaldirection of both the pusher wire 240 and the push rod 260.

The operation of the suturing instrument 200 is described with renewedreference to FIG. 2B and continued reference to FIG. 2C. The needledeployment mechanism 210 is actuated by pushing on the button 218, whichtranslates longitudinal movement along the shaft 220 to the pusher wire240, thereby moving the ferrule 252 along the track 254 andconcomitantly moving the carrier activation wire 256 along the channel274 within the curved portion 248. The carrier activation wire 256 movesthe needle carrier 258, through the opening 276. As the pusher wire 240responds to a larger displacement of the button 218, the ferrule 252reaches a terminal point as it travels along the track 254 and thisaction limits the outward travel of the carrier activation wire 254 toprevent overdriving and eliminate the possibility of expelling theneedle carrier 258 from the suturing instrument 200. As the button 218is released, the spring 232 biases the shaft 220 proximally, moving thepusher wire 240, the ferrule 252, and the carrier activation wire 254proximally along with the shaft 220, and the needle carrier 258 retractsinto the channel 274 of the distal portion 206.

With continued reference to FIG. 2C, the distal portion 206 of thesuturing instrument 200 may be rotated about the articulation joint 212by sliding the push rod 260 along a distal direction by pushing on thebutton 218, which translates longitudinal movement of the shaft 220 tothe push rod 260, which is attached to the shaft 220 at the push tube234 (FIG. 2D). The distal end 262 of the push rod 260 engages the distalportion 206 of the suturing instrument at the pocket 268. The pocket 268is a recessed area in the distal portion 206 for engagement andretainment of the distal end 262 of the push rod 260 as the distalportion 206 rotates about the articulation joint 212 out of alignmentwith the longitudinal axis 279 extending through the elongate member204. In one embodiment, the distal portion 206 is offset at an angle θof up to about 90 degrees relative to the longitudinal axis 279. In onepreferred embodiment, the distal portion 206 is offset at an angle ofabout 30 degrees relative to the longitudinal axis 279. In oneembodiment, the push rod 260 is biased distally by the spring 232 (FIG.2D) to offset the distal portion 206 out of alignment with thelongitudinal axis 279 in a normal state.

Preferably, the suturing instrument's component materials arebiocompatable. For example, the handle 202, the elongate member 204, andportions of the needle deployment mechanism 210 may be fabricated fromextruded, molded, or machined plastic material(s), such aspolypropylene, polycarbonate, or glass-filled polycarbonate. Othercomponents, for example the needle carrier 258, may be made of stainlesssteel. Other suitable materials will be apparent to those skilled in theart. The type of material(s) used to form a suture is not critical tothe present invention, as long as the material is biocompatible. Theuser selects the length, diameter, and characteristics of the suture tosuit a particular application. Additionally, mechanical components andoperation such as those disclosed in U.S. Pat. Nos. 5,364,408 and6,048,351, and commonly owned U.S. patent application Ser. No.10/210,984, each of which is incorporated by reference herein in itsentirety, may be employed with features of the invention.

FIGS. 3A to 3C depict another illustrative embodiment of a suturinginstrument 300. The elongate member 304 is pivotally connected to thedistal portion 306 at the articulation joint 312. The distal portion 306is offset relative to a longitudinal axis 379 by, for example, theaforementioned push rod arrangement. The suturing instrument 300includes an external sheath 380 (shown in partial section) disposedabout the elongate member 304 and having a distal portion 382 forengaging the distal portion 306 of the suturing instrument 300. Theinside diameter of the sheath 380 may be dimensioned such that it slidesfreely along the elongate member 304 or alternatively, the sheath 380may be of reduced inside diameter such that a slight friction-fitbetween the elongate member 304 and the sheath 380 is established. Thesheath 380 preferably extends proximally along the elongate member 304to permit articulation of the distal portion 306 by the user when thesuturing instrument 300 is inserted into the body of a patient.

In operation, the sheath 380 is moved by the user in a distal directionalong the elongate member 304 until the distal end 382 of the sheath 380engages the offset distal portion 306 of the suturing instrument 300. Asthe movement of the sheath 380 continues in a distal direction, thedistal portion 306 rotates about the articulation joint 312 intoalignment with the longitudinal axis 379 until the distal portion 382 ofthe sheath 380 is located at a position distal to the articulation joint312 (FIG. 3B). At this point, the distal portion 306 is substantiallycolinear to the longitudinal axis 379. The distal portion 306 may bedimensioned such that the distal end 382 of the sheath 380 may notextend past the distal portion 306 thereby avoiding overextension of thesheath 380. For example, the distal portion 306 may include a stop toprevent the sheath 380 from extending past the distal portion 306.

The sheath 380 and the push rod 360 may be operated in conjunction topositively actuate the distal portion 306 of the suturing instrument 300either out of alignment (using the push rod 360) or into alignment(using the sheath 380) with the longitudinal axis 379 of the elongatemember 304. Sliding the push rod 360 in a distal direction along theelongate member 304 engages the pocket 368 of the distal portion 306 ofthe suturing instrument 300 and effects rotation about the articulationjoint 312 out of alignment with the longitudinal axis 379. Inalternative embodiments, the push rod 360 is biased in a distaldirection or manually actuated such that the push rod 360 is disposedwithin the elongate member 304 with a friction-fit to provide apredetermined amount of resistance to movement along the longitudinalaxis 379 once the desired position of the push rod 360 is set.

FIGS. 4A to 4C depict another illustrative embodiment of a suturinginstrument 400. The suturing instrument 400 includes an external sheath480 (shown in section) with a distal end 482 and a flexible tab 484extending distally therefrom. The inside diameter of the sheath 480 maybe dimensioned such that it slides freely along the elongate member 404or alternatively, the sheath 480 may be of a reduced inside diametersuch that a slight friction-fit between the elongate member 404 and thesheath 480 is obtained. The sheath 480 is moved along the elongatemember 404 by sliding a proximal portion 483 of the sheath 480 towardthe distal portion 406. In alternative embodiments, the sheath 480 ismoved via an actuation means disposed at least partially in the proximalportion 408. The actuation means for moving the sheath 480 along theelongate member 404 includes, for example, a slideable pin and slotarrangement, a flute or rotational grove disposed on the sheath 480 forengaging a pin on the proximal portion 408 of the elongate member 404,which effects translational movement of the sheath 480 when the sheath480 is rotated. The suturing instrument 400 also includes a needle catch450 disposed proximate to the distal portion 206.

The flexible tab 484 includes a slot 486 (FIG. 4C) having a distal end490 for slideably engaging a fastener 488 that is fixedly attached tothe distal portion 406 of the suturing instrument 400. The fastener 488could be, for example, a pin, screw, rivet, or cleat. In operation, thesheath 480 is moved along the elongate member 404 to effect rotation ofthe distal portion 406 about the articulation joint 412. As the sheath480 is moved in a proximal direction toward the handle 402, the tab 484attached to the sheath 480 slides along the fastener 488, which isdisposed within the slot 486 of the tab 484, until the distal end 490 ofthe slot 486 engages the fastener 488. The length of the slot 486 isdimensioned so at to ensure that a distal end 490 of the slot 486engages the fastener 488 only after the distal end 482 of the sheath 480is located proximal to the articulation joint 412. As the distal end 490of the slot 486 engages the fastener 488, the distal portion 406 rotatesabout the articulation joint 412 out of alignment with the longitudinalaxis 479. The tab 484 is preferably flexible or hinged to helpfacilitate rotation of the distal portion 406.

A first stop 481A and a second stop 481B (FIG. 4B) prevent overrotationof the distal end 406 beyond a predetermined angular displacement. Inone embodiment, the distal portion 406 is offset from an angle θ ofabout 0 degrees to about 90 degrees relative to the longitudinal axis479. In one embodiment, the distal portion 406 rotates such that theangle θ is about 30 degrees relative to the longitudinal axis 479. Thefirst and second stops 481A, 481B engage adjacent areas of the distalportion 406 to provide the rotational limit of travel of the distalportion 406, thereby defining the size of the angle θ. The first stop481A limits the rotation of the distal portion 406 relative to thelongitudinal axis 479 in one direction. The second stop 481B limits therotation of the distal portion 406 relative to the longitudinal axis 479in an opposite direction. In one embodiment, the first and second stops481A, 481B are sized and configured to limit the rotation of the distalportion 406 about the articulation joint 412 so that the angle θ isapproximately 90 degrees. In another embodiment, the first and secondstops 481A, 481B are sized and configured to limit the rotation of thedistal portion 406 about the articulation joint 412 so that the angle θis approximately 30 degrees. Other magnitudes for angle θ arecontemplated to suit specific surgical needs.

FIG. 5 depicts another illustrative embodiment of a suturing instrument500. The suturing instrument 500 includes a carrier activation wire 556extending longitudinally from the ferrule 552 to the needle carrier 558in the distal portion 506 of the suturing instrument 500. In thisembodiment, a section of the activation wire 556 is routed in an “S”configuration (S-portion) 596 in the distal portion 506 proximate to thearticulation joint 512. The S-portion 596 is disposed within the carrieractivation wire channel 574. In a preferred embodiment, the activationwire 556 is constructed from nitinol. In addition, the suturinginstrument 500 includes a needle catch 550 disposed proximate to thedistal portion 506.

In operation, and in one preferred embodiment, the distal portion 506 ofthe suturing instrument and the needle carrier 558 are both actuated bymovement of the carrier activation wire 556 when the button 218 (FIGS.2D and 2E) is depressed. Prior to depressing the button 218, a tensileforce is maintained upon the carrier activation wire 556 by a spring 232(FIG. 2D). In an alternative embodiment, the carrier activation wire 556is maintained in tension by a separate compression spring (not shown).In one embodiment, the distal portion 506 is maintained out of alignmentwith the longitudinal axis 579 so that the angle θ is approximately 30degrees. The carrier activation wire 556 is not rigidly coupled to thedistal portion 506 of the suturing instrument 500, but is retainedwithin the distal portion 506 by the binding force arising from thefriction between the carrier activation wire 556 and the channel 574.More particularly, the configuration of the S-portion 596 of the carrieractivation wire 556 contained with the channel 574 provides additionalbinding force to the carrier activation wire 556 resulting from thecurvature of the channel 574 in proximity with the S-portion 596. Undertension, the carrier activation wire 556 will occupy the shortest pathwithin the channel 574 thereby biasing the distal portion 506 about thearticulation joint 512 and out of alignment with the longitudinal axis579 at an initial angle θ of about 30 degrees. The tension of thecarrier activation wire 556 may retain the distal portion 506 out ofalignment with the longitudinal axis 579 at other angles θ.

When the force is initially applied to the actuation button 218, thedistal portion 506 begins to rotate about the articulation joint 512into alignment with the longitudinal axis 579. This rotation continuesuntil the distal portion 506 meets resistance, such as that provided bybody tissue (see FIG. 6). Once the resistance to rotation of the distalportion 506 exceeds the binding resistance of the carrier activationwire 556, the distal portion 506 ceases rotation about the articulationjoint 512. With the continued application of force, the carrieractivation wire 556 moves in a distal direction advancing the needlecarrier 558 from the opening 576 and into the body tissue (as shown inphantom in FIG. 6). The threshold resistance required to overcome thebinding resistance of the carrier activation wire 556 within the channel574 may be predetermined and established for particular surgicalprocedures to effect the performance characteristics of the suturinginstrument 500. The selection of materials and surfaces for the channel574 and the carrier activation wire 556, as well as the curvature of theS-portion 596 may also be varied to change the threshold resistance. Inone embodiment, the suturing instrument 500 may include a push rod 560and a sheath 580 for an alternative or additional means of actuating thedistal portion 506 into alignment or out of alignment with thelongitudinal axis 579. The structure and operation of the push rod 560and the sheath 580 are as described in the aforementioned embodiments.

FIG. 6 depicts a clinical application with the suturing instrument 500of FIG. 5, showing a schematic representation of an endoscopicprocedure. The suturing instrument 500 may be inserted into the bodythrough a sleeve 598 (for example, a trocar or cannula) to facilitateaccess to and from the body cavity. Before the suturing instrument 500is inserted into the sleeve 598, the distal portion 506 may bearticulated such that it is in a substantially linear configuration withrespect to the elongate member 504. This may be achieved by using thecarrier activation wire 556 as described above or by using the sheath580 as described in the aforementioned embodiments. Specifically, and inone embodiment, the sheath 580 may be used to straighten the suturinginstrument 500 (by rotating the distal portion 506 into alignment withthe longitudinal axis 579 without requiring the persistent depression ofthe actuator button 218 (see FIG. 2B) for maintaining the distal portion506 in this straightened position. Once the sheath 580 is moved alongthe elongate member 504 in a distal direction and the suturinginstrument 500 is substantially linear, the instrument 500 may beinserted into the sleeve 598. Once inserted, the sheath 580 is movedalong the elongate member 504 in a proximal direction until the distalportion 506 is out of alignment with the longitudinal axis 579. Thedistal portion 506 is now ready for articulation within the body cavity.After inserting the suturing instrument 500 through the opening of thesleeve 598 and into the body, the distal end 506 may be rotated aboutthe articulation joint 512 by any of the aforementioned means,individually or in combination. The suturing instrument 500 may beoperated in either the offset or linear configuration. For example, theneedle carrier 558 may be advanced when the distal portion 506 is eitherout of alignment with or in alignment with the longitudinal axis 579. Infurther embodiments, the needle carrier 558 may be advanced when thesuturing instrument 500 is in an intermediate position between theoffset and linear configurations.

Other embodiments incorporating the concepts disclosed herein may beused without departing from the spirit and scope of the invention. Thedescribed embodiments are to be considered in all respects as onlyillustrative and not restrictive. Therefore, it is intended that thescope of the invention be only limited by the following claims.

1. A suturing instrument comprising: an elongate member including alongitudinal axis and a distal portion offset from the longitudinalaxis; and a sheath slideably disposed about the elongate member, thesheath positionable in contact with the distal portion to actuate thedistal portion relative to the longitudinal axis.
 2. The suturinginstrument of claim 1, wherein the distal portion is pivotally coupledto the elongate member.
 3. The suturing instrument of claim 1, whereinthe distal portion is biased up to about 90 degrees relative to thelongitudinal axis.
 4. The suturing instrument of claim 1, wherein thedistal portion comprises a range of actuation from about 1 degree toabout 90 degrees.
 5. The suturing instrument of claim 1 furthercomprising a needle deployment mechanism at least partially housed inthe elongate member.
 6. The suturing instrument of claim 5, wherein theneedle deployment mechanism comprises: a needle carrier at leastpartially disposed in the distal portion for holding a needle; and anactuator at least partially disposed within the elongate member andcoupled to the needle carrier for advancing the needle out of an openingdefined by the distal portion of the elongate member.
 7. The suturinginstrument of claim 6 further comprising a needle catch disposedproximate the distal portion of the elongate member and configured toreceive the needle.
 8. The suturing instrument of claim 1, wherein thedistal portion is offset from the longitudinal axis by a push rod andspring arrangement at least partially disposed in the elongate member.9. The suturing instrument of claim 1, wherein the distal portion of theelongate member can rotate relative to a remainder of the elongatemember.
 10. A suturing instrument comprising: an elongate member; a headcoupled to a distal portion of the elongate member; and a sheathdisposed about and slideable along a length of the elongate memberwherein sliding the sheath proximally causes the head to pivot.
 11. Thesuturing instrument of claim 10, further comprising a tab extending froma distal end of the sheath and a fastener coupling the tab to the head.12. The suturing instrument of claim 11, wherein the fastener couplesthe tab to the head via a slot defined by the tab and sliding the sheathproximally causes the tab to engage the fastener.
 13. The suturinginstrument of claim 11, wherein the sheath extends substantially theentire length of the elongate member.
 14. The suturing instrument ofclaim 11, wherein sliding the sheath proximally relative to the elongatemember, biases the head offset from a longitudinal axis of the elongatemember and sliding the sheath distally causes the head to pivot intosubstantial alignment with the longitudinal axis.
 15. The suturinginstrument of claim 11 further comprising a needle deployment mechanismat least partially housed in the elongate member.
 16. The suturinginstrument of claim 15, wherein the needle deployment mechanismcomprises: a needle carrier at least partially disposed in the head forholding a needle; and an actuator at least partially disposed within theelongate member and coupled to the needle carrier for advancing theneedle out of an opening defined by the head.
 17. The suturinginstrument of claim 16 further comprising a needle catch disposed on thehead and configured to receive the needle.
 18. A suturing instrumentcomprising: an elongate member including a longitudinal axis; a headcoupled to the elongate member; and a needle deployment mechanism atleast partially housed within the elongate member, the needle deploymentmechanism comprising, a needle carrier at least partially disposed inthe head for holding a needle, and a carrier activation wire coupled tothe needle carrier and extending substantially along the longitudinalaxis of the elongate member, the activation wire biasing the head offsetfrom the longitudinal axis of the elongate member when in tension andarticulating the head relative to the longitudinal axis andpreferentially deploying the needle from the head when in compression.19. The suturing instrument of claim 18 further comprising a sheathdisposed about the elongate member and slideable along a length of theelongate member, the sheath including a distal end for engaging andarticulating the head relative to the longitudinal axis of the elongatemember.
 20. The suturing instrument of claim 18, wherein the head isoffset up to about 90 degrees relative to the longitudinal axis.
 21. Thesuturing instrument of claim 18, wherein the head comprises a range ofarticulation from about 1 degree to about 90 degrees.
 22. The suturinginstrument of claim 18 further comprising a needle catch disposed on thehead and configured to receive the needle.
 23. The suturing instrumentof claim 18, wherein the head is offset from the longitudinal axis by apush rod and spring arrangement at least partially disposed in theelongate member.